Energy and Exergy Analysis of a Cruise Ship

Artikel i vetenskaplig tidskrift, 2018

In recent years, the International Maritime Organization agreed on aiming to reduceshipping’s greenhouse gas emissions by 50% with respect to 2009 levels. Meanwhile, cruise shiptourism is growing at a fast pace, making the challenge of achieving this goal even harder.The complexity of the energy system of these ships makes them of particular interest from anenergy systems perspective. To illustrate this, we analyzed the energy and exergy flow rates of acruise ship sailing in the Baltic Sea based on measurements from one year of the ship’s operations.The energy analysis allows identifying propulsion as the main energy user (46% of the total) followedby heat (27%) and electric power (27%) generation; the exergy analysis allowed instead identifyingthe main inefficiencies of the system: while exergy is primarily destroyed in all processes involvingcombustion (76% of the total), the other main causes of exergy destruction are the turbochargers,the heat recovery steam generators, the steam heaters, the preheater in the accommodation heatingsystems, the sea water coolers, and the electric generators; the main exergy losses take place in theexhaust gas of the engines not equipped with heat recovery devices. The application of clustering ofthe ship’s operations based on the concept of typical operational days suggests that the use of fivetypical days provides a good approximation of the yearly ship’s operations and can hence be usedfor the design and optimization of the energy systems of the ship.